the present invention relates generally to bags wherein a principal or main body had folded or collasped within it a top or secondary bag section, which can be withdrawn to effectively double the capacity of the bag. Bags of this type have been disclosed in U.S. Pat. Nos. 3,229,741; 1,810,347; 2,212,390; and 2,729,257. Some of the foregoing include closure means for the respective main and secondary sections of the bag and other do not, while none of the collapsible/expandable bags heretofore known are suitable in a modern sense to be used as casual or sport type luggage. It is the purpose of the present invention to fulfill this need.